ZIKA I: Ticker tape of the damned

TRACKING VIRUSES Dr. Isaac Bogoch, looking at the distribution of various bats thought to be reservoirs of the Ebola virus.

I just finished writing a book on invasive species. Also known as alien, nonindigenous, nonnative or exotic, these are organisms transported and introduced outside their native ranges that then establish to become problematic in some way or another. I've periodically covered some in this space, and written a feature on the Sea to Sky Invasive Species Council ("Guardians at the Gate," Pique, 24 September 2014). One thing that became clear as I worked on the book was how many of these problems were actually preventable: identified in early stages by competent professionals whose objective prognostications were either portrayed as sky-is-falling sensationalism or — for reasons of politics, money, or sheer apathy — ignored by the rest of us. Nowhere is this truer than the realm of emerging infectious diseases, where pathogens invasive in their own right are often additionally vectored by invasive species. One example has recently become particularly instructive.

Toronto General Hospital, that city's largest medical center, sprawls several blocks at the heart of a cluster of patient care and health research facilities associated with the University of Toronto. On a steamy day last August I pulled up curbside to fight through dozens of people who had appointments to see a wide range of specialists. I was also there to see a specialist: Dr. Isaac Bogoch. Tall, lean, and moving with purpose, the Assistant Professor in U of T's Department of Medicine and a tropical disease specialist at Toronto General met me at a busy Starbucks in the lobby of one of the 200-year-old institution's newer buildings. I grabbed a coffee, he a green tea, and we rode an elevator to the "penthouse" — as he jokingly referenced his office.

Many of the interviews I conducted for my book were exploratory in nature, but I knew exactly where to start with Bogoch. He'd been tracking and modelling emerging and re-emerging diseases influenced by socioeconomic and agricultural patterns, climatic and ecological change, globalization and accelerated rates of air travel. As reported in this column last year ("Spring Fever," Pique, 22 January 2015), Bogoch and other researchers made a spot-on prediction in 2014 about the potential for spread of the emerging chikungunya virus from the Caribbean, in which international travel by infected persons and the increasing geographic availability of "competent vectors" — Bogoch's polite way of framing the invasive mosquito species required for transmission of the CHK-V virus — set the stage for chikungunya's introduction and spread in the Americas. Coupled with an increase in appropriate environmental factors for both vector and virus (e.g., average temperature above 20C), it added up to 1.5 million confirmed cases as of the date of my visit, only 18 months after chikungunya was first reported. Although the illness was mild for most, the speed of spread was worrying; it was also ruining many vacation plans for the Caribbean — with a resultant heavy economic impact. As Bogoch explained, "If someone asks me whether their kids might get chikungunya on their vacation, well... I can't say no."

After we'd chatted about the latest chikungunya figures, we moved on to the current state of HIV (invasive and zoontoic in having originated in another species), and the West Africa Ebola crises (for which he'd modelled potential spread through air travel). While we were talking, his computer screen pinged with notice of a cholera outbreak in a prison in Kathmandu, Nepal. Having headed post-earthquake disease prevention and treatment teams in that country, this was of particular interest. "It's fecal-oral transmission," he said, "so it will rip right through a prison."

Of more interest to me was the source of the alert.

Turns out there's a virtual rabbit hole where the interests of disease specialists and invasion scientists converge: the website ProMED-mail (ProMED = Program for Monitoring Emerging Diseases) which Bogoch and I then spent several minutes perusing. For science geeks and fans of black biology, disease reports on plants and animals (including humans) from around the globe were like a bottomless bag of Doritos to a stoner — you couldn't stop consuming them. To highlight just a fraction of the pathogenic exotica, in addition to Nepal, Asia was awash in cholera, along with dysentery and various hemorrhagic fevers; likewise the Americas were lousy with chikungunya, hantavirus, bubonic plague, anthrax, encephalitis, West Nile, and numerous tick-borne illnesses; invasive tiger mosquitoes were tracking in Australia, Belgium and France, the latter also reporting dengue; fatalities from toxic algae occurred in the U.S. and Britain; and there were updates galore from Africa's waning Ebola frontier. Scrolling through was like watching a live broadcast of a natural disaster, with a similarly potent "train wreck" draw. Yet such facile comparisons belie ProMED's true utility.

As an exemplary use of modern technology and communications, you could immediately see how monitoring the feed offered researchers like Bogoch an ongoing, 24/7 signal to help determine when crafting models might help public health authorities get ahead of a problem. As an example, Bogoch pointed to the spread of another obscure little bug he'd been modelling: only a few months later, Zika virus would hit the news.

Next week - a history of modelling the Zika disease

Leslie Anthony is a Whistler-based author, editor, biologist and bon vivant who has never met a mountain he didn't like.